Experiment to confirm the 1:2:1 ratio of TT, Tt, and tt trait combination in the F2 generation:

To confirm that the F2 generation indeed follows a 1:2:1 ratio of TT, Tt, and tt trait combinations, we can conduct a test cross experiment. The test cross involves crossing an individual with a dominant phenotype (such as TT) with an individual that has a recessive phenotype (such as tt). By analyzing the offspring from this cross, we can determine the ratio of different trait combinations.

Procedure:

1. Select a purebred individual with the dominant trait (TT) and a purebred individual with the recessive trait (tt).

2. Cross the purebred dominant individual with the purebred recessive individual. This mating is known as a test cross.

3. Allow the offspring to grow and observe their phenotypes.

4. Count the number of individuals displaying the dominant trait (TT), the heterozygous trait (Tt), and the recessive trait (tt).

5. Record the number of individuals for each phenotype.

Data Analysis:

1. Calculate the ratio of individuals with each trait combination.

2. Add up the number of individuals with the dominant trait (TT) and the recessive trait (tt). If the ratio is indeed 1:2:1, the sum of these two numbers should be double the number of individuals with the heterozygous trait (Tt).

3. Divide the number of individuals with the dominant trait (TT) and the recessive trait (tt) by the number of individuals with the heterozygous trait (Tt). The ratio of these two numbers should be approximately 1:2:1.

Mendel's Contributions:

Gregor Mendel, known as the father of genetics, conducted numerous experiments on pea plants and made several significant contributions to the field of genetics.

1. Mendel formulated the Law of Segregation, which states that during the formation of gametes, the paired alleles separate or segregate randomly. This law explains why traits can reappear in later generations.

2. Mendel also observed the Law of Independent Assortment, which states that the inheritance of one trait is independent of the inheritance of another trait. This law explains the diversity of offspring traits in a cross.

3. Through his experiments, Mendel demonstrated the concept of dominant and recessive traits. He proposed that each individual has two copies of each gene, known as alleles, and the dominant allele masks the expression of the recessive allele.

4. Mendel's experiments and observations provided a foundation for modern genetics. His work laid the groundwork for understanding inheritance patterns, the concept of genes, and the principles of heredity.

Overall, Mendel's contributions have had a profound impact on the field of genetics, and his laws and principles continue to be the basis for understanding inheritance patterns in various organisms.